Bioengineered vascular grafts with a pathogenic TGFBR1 variant model aneurysm formation in vivo and reveal underlying collagen defects.

Thoracic aortic aneurysm (TAA) is a life-threatening vascular disease frequently associated with underlying genetic causes. An inadequate understanding of human TAA pathogenesis highlights the need for better disease models. Here, we established a functional human TAA model in an animal host by combining human induced pluripotent stem cells (hiPSCs), bioengineered vascular grafts (BVGs), and gene editing. We generated BVGs from isogenic control hiPSC-derived vascular smooth muscle cells (SMCs) and mutant SMCs gene-edited to carry a Loeys-Dietz syndrome (LDS)-associated pathogenic variant (TGFBR1A230T). We also generated hiPSC-derived BVGs using cells from a patient with LDS (PatientA230T/+) and using genetically corrected cells (Patient+/+). Control and experimental BVGs were then implanted into the common carotid arteries of nude rats. The TGFBR1A230T variant led to impaired mechanical properties of BVGs, resulting in lower burst pressure and suture retention strength. BVGs carrying the variant dilated over time in vivo, resembling human TAA formation. Spatial transcriptomics profiling revealed defective expression of extracellular matrix (ECM) formation genes in PatientA230T/+ BVGs compared with Patient+/+ BVGs. Histological analysis and protein assays validated quantitative and qualitative ECM defects in PatientA230T/+ BVGs and patient tissue, including decreased collagen hydroxylation. SMC organization was also impaired in PatientA230T/+ BVGs as confirmed by vascular contraction testing. Silencing of collagen-modifying enzymes with small interfering RNAs reduced collagen proline hydroxylation in SMC-derived tissue constructs. These studies demonstrated the utility of BVGs to model human TAA formation in an animal host and highlighted the role of reduced collagen modifying enzyme activity in human TAA formation.

Unraveling the genetic collagen connection: clinical and therapeutic insights on genetic connective tissue disorders.

Hereditary connective tissue disorders include more than 200 conditions affecting different organs and tissues, compromising the biological role of the extracellular matrix through interference in the synthesis, development, or secretion of collagen and/or its associated proteins. The clinical phenotype includes multiple signs and symptoms, usually nonspecific but of interest to rheumatologists because of musculoskeletal involvement. The patient´s journey to diagnosis is long, and physicians should include these disorders in their differential diagnoses of diseases with systemic involvement. In this review, insights for the diagnosis and treatment of osteogenesis imperfecta, hypermobility spectrum disorder/Ehlers-Danlos syndrome, Marfan, Loeys-Dietz, and Stickler syndromes are presented.

The Impact of Pregnancy in Patients with Thoracic Aortic Disease: Epidemiology, Risk Assessment, and Management Considerations.

Thoracic aortic disease (TAD) poses substantial risks during pregnancy, particularly for women with genetic conditions such as Marfan syndrome, Loeys-Dietz syndrome, and vascular Ehlers-Danlos syndrome. This review examines the epidemiology, risk assessment, and management of TAD in pregnancy. Preconception counseling is vital considering the hereditary nature of TAD and potential pregnancy-related complications. Genetic testing and imaging surveillance aid in risk assessment. Medical management, including beta-blockade and strict blood pressure control, is essential throughout pregnancy. Surgical interventions may be necessary in certain cases. A multidisciplinary approach involving cardiologists, obstetricians, cardiac surgeons, anesthesiologists, and other specialists with expertise in cardio-obstetrics is essential for optimal outcomes. Patient education and shared decision-making play vital roles in navigating the complexities of TAD in pregnancy and improving maternal and neonatal outcomes.

Cardiovascular and obstetrical outcomes among delivering patients with Marfan or Loeys-Dietz syndrome: a retrospective analysis by hospital delivery setting.

BACKGROUND: Pregnancy is a high-risk time for patients with Marfan syndrome or Loeys-Dietz syndrome because of the risk for cardiovascular complications, including the risk for aortic dissection. Little is known about the differences in obstetrical and cardiac outcomes based on delivery hospital setting (academic or academic-affiliated vs community medical centers). OBJECTIVE: This study aimed to evaluate the obstetrical and cardiac outcomes of patients with Marfan syndrome or Loeys-Dietz syndrome based on delivery hospital setting. STUDY DESIGN: This was a secondary analysis of a retrospective, observational cohort study of singleton pregnancies among patients with a diagnosis of Marfan syndrome or Loeys-Dietz syndrome from 1990 to 2016. Patients were identified through the Marfan Foundation, the Loeys-Dietz Syndrome Foundation, or the Cardiovascular Connective Tissue Clinic at Johns Hopkins Hospital. Data were obtained via self-reported obstetrical history and verified by review of medical records. Nonparametric analyses were performed using Fisher's exact tests and Wilcoxon rank-sum tests. RESULTS: A total of 273 deliveries among patients with Marfan syndrome or Loeys-Dietz syndrome were included in this analysis (Table 1). More patients who had a known diagnosis before delivery of either Marfan syndrome or Loeys-Dietz syndrome delivered at an academic hospital as opposed to a community hospital (78.6% vs 59.9%; P=.001). Patients with Marfan syndrome or Loeys-Dietz syndrome who delivered at academic centers were more likely to have an operative vaginal delivery than those who delivered at community centers (23.7% vs 8.6%; P=.002). When the indications for cesarean delivery were assessed, connective tissue disease was the primary indication for the mode of delivery at community centers when compared with academic centers (55.6% vs 43.5%; P=.02). There were higher rates of cesarean delivery for arrest of labor and/or malpresentation at community hospitals than at academic centers (23.6% vs 5.3%; P=.01). There were no differences between groups in terms of the method of anesthesia used for delivery. Among those with a known diagnosis of Marfan syndrome or Loeys-Dietz syndrome before delivery, there were increased operative vaginal delivery rates at academic hospitals than at community hospitals (27.2% vs 15.1%; P=.03) (Table 2). More patients with an aortic root measuring ≥4 cm before or after pregnancy delivered at academic centers as opposed to community centers (33.0% vs 10.2%; P=.01), but there were no significant differences in the median size of the aortic root during pregnancy or during the postpartum assessment between delivery locations. Cardiovascular complications were rare; 8 patients who delivered at academic centers and 7 patients who delivered at community centers had an aortic dissection either in pregnancy or the postpartum period (P=.79). CONCLUSION: Patients with Marfan syndrome or Loeys-Dietz syndrome and more severe aortic phenotypes were more likely to deliver at academic hospitals. Those who delivered at academic hospitals had higher rates of operative vaginal delivery. Despite lower frequencies of aortic root diameter >4.0 cm, those who delivered at community hospitals had higher rates of cesarean delivery for the indication of Marfan syndrome or Loeys-Dietz syndrome. Optimal delivery management of these patients requires further prospective research.

Cardiovascular pathology, inheritance and prognosis in a familial cohort of Loeys-Dietz type III.

INTRODUCTION: Loeys-Dietz syndrome (LDS) is a heritable disease that is the result of dysregulation of the transforming growth factor beta (TGFß) pathway. The pathogenic variants associated with the condition are linked to aortic aneurysms and dissections along with other cardiovascular and non-cardiovascular abnormalities. LDS type III is associated with pathogenic variants in the SMAD3 gene responsible for signally in the TGFß pathway. Most of the current knowledge of LDS stems from studies of LDS I and II patient with limited data on large cohorts of LDS III patients. We sought to identify the prevalence and course of cardiovascular diseases in a large familial cohort of LDS III patients and also to compare these findings with a previously described cohort of similar size with the identical pathogenic variant. METHODS: The cohort was identified by systematic genetic screening of a familial cohort identified through a single proband. Data was collected from retrospective chart review of patients identified to be affected by the syndrome. RESULTS: Screening of 97 patients identified 19 patients (16 through genetic testing and 3 through phenotypic screening of untested direct descendants of genetically positive individuals). The prevalence of cardiovascular abnormalities was 84%. There was significant intrafamilial phenotypic variability within the cohort with the predominant cardiovascular abnormality being mitral valve disease followed by aortic disease. 92% of patients >18 years of age had osteoarthritis which is a further hallmark of LDS III. CONCLUSION: LDS III sets itself apart from the more widely studied LDS types I and II cardiovascular phenotypes by presenting later in life and tending to be more strongly associated with mitral valve disease.

Physical fitness in children with Marfan and Loeys-Dietz syndrome: associations between cardiovascular parameters, systemic manifestations, fatigue, and pain.

Children with Marfan (MFS) and Loeys-Dietz syndrome (LDS) report limitations in physical activities, sports, school, leisure, and work participation in daily life. This observational, cross-sectional, multicenter study explores associations between physical fitness and cardiovascular parameters, systemic manifestations, fatigue, and pain in children with MFS and LDS. Forty-two participants, aged 6-18 years (mean (SD) 11.5(3.7)), diagnosed with MFS (n = 36) or LDS (n = 6), were enrolled. Physical fitness was evaluated using the Fitkids Treadmill Test's time to exhaustion (TTE) outcome measure. Cardiovascular parameters (e.g., echocardiographic parameters, aortic surgery, cardiovascular medication) and systemic manifestations (systemic score of the revised Ghent criteria) were collected. Pain was obtained by visual analog scale. Fatigue was evaluated by PROMIS® Fatigue-10a-Pediatric-v2.0-short-form and PROMIS® Fatigue-10a-Parent-Proxy-v2.0-short-form. Multivariate linear regression analyses explored associations between physical fitness (dependent variable) and independent variables that emerged from the univariate linear regression analyses (criterion p < .05). The total group (MFS and LDS) and the MFS subgroup scored below norms on physical fitness TTE Z-score (mean (SD) -3.1 (2.9); -3.0 (3.0), respectively). Univariate analyses showed associations between TTE Z-score aortic surgery, fatigue, and pain (criterion p < .05). Multivariate analyses showed an association between physical fitness and pediatric self-reported fatigue that explained 48%; 49%, respectively, of TTE Z-score variance (F (1,18) = 18.6, p ≤ .001, r2 = .48; F (1,15) = 16,3, p = .01, r2 = .49, respectively).    Conclusions: Physical fitness is low in children with MFS or LDS and associated with self-reported fatigue. Our findings emphasize the potential of standardized and tailored exercise programs to improve physical fitness and reduce fatigue, ultimately enhancing the physical activity and sports, school, leisure, and work participation of children with MFS and LDS. What is Known: • Marfan and Loeys-Dietz syndrome are heritable connective tissue disorders and share cardiovascular and systemic manifestations. • Children with Marfan and Loeys-Dietz syndrome report increased levels of disability, fatigue and pain, as well as reduced levels of physical activity, overall health and health-related quality of life. What is New: • Physical fitness is low in children with Marfan and Loeys-Dietz syndrome and associated with self-reported fatigue. • Our findings emphasize the potential of standardized and tailored exercise programs to improve physical fitness and reduce fatigue, ultimately enhancing the physical activity and sports, school, leisure, and work participation of children with Marfan and Loeys-Dietz syndrome.

Loeys-Dietz syndrome and Goldenhar syndrome unveiled together.

Haemifacial microsomia is an asymmetrical congenital tissue malformation developed from the first and second branchial arches with or without multi-system involvement. Alternatively recognised as Goldenhar syndrome or oculoauriculovertebral spectrum (OAVS), it is an aetiologically heterogeneous group of disorders showing dominant trends in inheritable form.We present a case of a boy in early childhood with concomitant craniofacial features of craniofacial microsomia with Loeys-Dietz syndrome. He had a unilateral hypoplastic face, asymmetrical ear malformations and multiple preauricular tags with epibulbar dermoid (features suggestive of Goldenhar syndrome). On detailed clinical evaluation, he met Beighton's criteria and was diagnosed with arterial tortuosity. Further molecular testing confirmed the diagnosis of Loeys-Dietz syndrome type II.Loeys-Dietz syndrome is characterised by aortic root enlargement or type A dissection with or without other vascular malformations and facial midline defects. Molecular testing is required to establish the diagnosis because of overlapping features with other connective tissue disorders.

Loeys-Dietz syndrome with a novel in-frame SMAD3 deletion diagnosed as a result of postpartum aortic dissection: A case report.

OBJECTIVE: Loeys-Dietz syndrome (LDS) is a rare, autosomal dominant connective tissue disorder which can aggressively affect the aortic vasculature. Limited information is available regarding its impact on pregnancy and postpartum outcomes. CASE REPORT: A pregnant 38-year-old nulliparous woman with mild aortic regurgitation and family history of aortic aneurysms presented with an aortic root measuring 49 mm. Despite concerns of an underlying connective tissue disorder, a definitive diagnosis was not reached. She delivered under strict blood pressure control, developed intractable uterine atony, and underwent uterine artery embolization. On the second postpartum day, aortic dissection was incidentally diagnosed, and aortic root replacement surgery was performed. Genetic testing revealed a novel in-frame SMAD3 deletion [NM_005902.4: c.703_708del, (p.Ile235_Ser236del)], leading to a diagnosis of LDS type 3. CONCLUSION: This case highlights the high postpartum aortic dissection risk in women with LDS, emphasizing the importance of early diagnosis in pregnant women with few clinical symptoms.

Endovascular aortic repair in patients with Marfan and Loeys-Dietz syndrome is safe and durable when employed by a multi-disciplinary aortic team.

OBJECTIVES: The aim of this study was to report on mid-term outcomes after endovascular aortic repair (EVAR) in patients with Marfan (MFS) or Loeys-Dietz (LDS) syndrome. METHODS: We analysed data from 2 European centres of patients with MFS and LDS undergoing EVAR. Patients were analysed based on (i) timing of the procedure (planned versus emergency procedure) and (ii) the nature of the landing zone (safe versus non-safe). The primary end-point was freedom from reintervention. Secondary end-points were freedom from stroke, bleeding and death. RESULTS: A population of 419 patients with MFS (n = 352) or LDS (n = 67) was analysed for the purpose of this study. Thirty-nine patients (9%) underwent EVAR. Indications for thoracic endovascular aortic repair or EVAR were aortic dissection in 13 (33%) patients, aortic aneurysm in 22 (57%) patients and others (intercostal patch aneurysm, penetrating atherosclerotic ulcer, pseudoaneurysm, kinking of frozen elephant trunk (FET)) in 4 (10%) patients. Thoracic endovascular repair was performed in 34 patients, and abdominal endovascular aortic repair was performed in 5 patients. Mean age at 1st thoracic endovascular aortic repair/EVAR was 48.5 ± 15.4 years. Mean follow-up after 1st thoracic endovascular aortic repair/EVAR was 5.9 ± 4.4 years. There was no statistically significant difference in the rate of reinterventions between patients with non-safe landing zone and the patients with safe proximal landing zone (P = 0.609). Furthermore, there was no increased probability for reintervention after planned endovascular intervention compared to emergency procedures (P = 0.916). Mean time to reintervention, either open surgical or endovascular, after planned endovascular intervention was in median 3.9 years (95% confidence interval 2.0-5.9 years) and 2.0 years (95% confidence interval -1.1 to 5.1 years) (P = 0.23) after emergency procedures. CONCLUSIONS: EVAR in patients with MFS and LDS and a safe landing zone is feasible and safe. Endovascular treatment is a viable option when employed by a multi-disciplinary aortic team even if the landing zone is in native tissue.

Familial visceral branch artery aneurysms in Loeys-Dietz syndrome.

Loeys-Dietz syndrome (LDS) is an autosomal dominant heritable disorder due to pathogenic variants in one of several genes involved in TGF-ß (transforming growth factor-beta) signalling. LDS is associated with aortic aneurysm and dissection. LDS may also lead to extra-aortic aneurysms, the majority of which occur in the head and neck vasculature. Visceral aneurysms are uncommon, and no cases of distal superior mesenteric artery (SMA) branch aneurysms in patients with LDS have been reported. Three related females with TGFBR1-related LDS developed distal SMA branch artery aneurysms involving the ileocolic and jejunal arteries. Endovascular or surgical intervention was performed in each. The presence and severity of arterial, craniofacial, and cutaneous features of LDS in these patients are variable. TGFBR1-related LDS may rarely lead to SMA branch artery aneurysms that can develop later in life. Surgical and endovascular procedures can successfully treat these aneurysms, but data to guide size thresholds and optimal treatment strategies are lacking.

Evaluating Variation in the Cardiac Management of Children with Hereditary Thoracic Aortic Disease in the United States.

Hereditary thoracic aortic diseases (HTAD) such as Marfan syndrome (MFS), Loeys-Dietz syndrome (LDS), and vascular Ehlers-Danlos syndrome (VEDS) frequently result in complex cardiovascular pathology that can lead to premature death. However, given limited research and lack of detailed pediatric management guidelines, practice in the U.S. is largely guided by personal experience and/or advice from other professionals. A REDCap survey was composed that covered topics including genetic testing, imaging, and medication choice (all in children), among others. After piloting, the survey was distributed via email and advertised on PediHeartNet. Email addresses of providers were obtained through an established aortic research collaborative and a clinic directory offered through The Marfan Foundation. There were 64 survey responses (pediatric cardiologists 66%; geneticists 13%, genetic counselors 6%; the remaining 15% was comprised of a combination of cardiothoracic surgeons, adult cardiologists, adult congenital specialists, combined cardiology and genetics specialist, nurse practitioners, physician assistants, and nurse coordinators). The most supported indication for genetic evaluation in a child with mild aortic root dilation was family history of thoracic aortic dissection (100%), in contrast to mild root dilation with no other HTAD features (39% supported, 45% did not, 15% saying it would depend on other factors). The majority would start medical therapy in MFS at an aortic root z-score of 2, however differences existed regarding medication preferences for initiation (47% angiotensin receptor blockers, 36% beta blockers, 17% would not or cannot prescribe medication/defer medication choice to another provider). Variation existed for cross-sectional imaging indications and modality and for exercise restrictions, although on average respondents were more lenient than the Bethesda guidelines. While there are areas of general agreement in the cardiac management of children with HTAD, there are also several areas of considerable variation. This highlights the need for additional study in these areas with the ultimate goal of creating consensus guidelines.

Arterial tortuosity in pediatric Loeys-Dietz syndrome patients.

Loeys-Dietz syndrome (LDS) is an autosomal connective tissue disorder commonly presenting with hypertelorism, bifid uvula, aortic aneurysms, and arterial tortuosity. The aim of the present study was to investigate differences in tortuosity index (TI) between genotypes of LDS, possible progression over time and its use as an adjunctive prognostic tool alongside aortic dimensions to aid timely surgical planning in pediatric patients. A retrospective observational study of pediatric LDS patients referred to our center (November 2012-February 2021) was conducted. Using magnetic resonance angiography (MRA) with 3D maximum intensity projection volume-rendered angiogram, arterial TI was measured. Twenty three patients had genetically confirmed LDS with at least one head and neck MRA and 19 had no less than one follow-up MRA available. All patients presented arterial tortuosity. Patients with TGFBR2 variants had greater values of TI compared to patients with TGFB2 variants (p = 0.041). For patients who did not undergo surgery (n = 18), z-scores at the level of the sinus of Valsalva showed a significant correlation with vertebral TI (rs = 0.547). There was one death during follow-up. This study demonstrates that patients with LDS and TGFBR2 variants have greater values of TI than patients with TGFB2 variants and that greatest values of TI are associated with increased aortic root z-scores. Furthermore, as TI decreases over time, less frequent neuroimaging follow-up can be considered. Nevertheless, additional studies are needed to better define more accurate risk stratification and long-term surveillance in these patients.

[Depressive and anxiety symptoms in hereditary connective tissue disorders : case description and systematic literature review]. / Depressieve en angstklachten bij erfelijke bindweefselaandoeningen: casus en systematisch literatuuroverzicht.

Hereditary connective tissue disorders are a broad group of congenital disorders that are characterized by a pathological weakness of the connective tissue as a result of an incorrect genesis, leading to multisystem complaints. We describe a 14-year-old patient with the hereditary connective tissue disorder Loeys-Dietz syndrome who was admitted to a child psychiatric crisis unit because of depressive and anxiety symptoms. A systematic literature search was carried out to analyze the prevalence of depressive and anxiety symptoms in individuals with hereditary connective tissue disorders Loeys-Dietz syndrome, Ehlers-Danlos syndrome and Marfan syndrome, to identify a possible association between these disorders and explanations for this. We conclude that there is an increased incidence of depression and anxiety symptoms in which pain, fatigue, social support and functioning, quality of life and functional limitations seem to play a role. There is a need for further research to determine exactly which factors contribute and how these can be targeted in prevention and treatment.

[Clinical and genetic analysis of a patient with Loeys-Dietz syndrome due to variant of TGFBR2 gene].

OBJECTIVE: To explore the genetic basis of a patient with clinically suspected Loeys-Dietz syndrome (LDS). METHODS: A child who had presented at Beijing Anzhen Hospital in September 2018 was selected as the study subject. Clinical data and family history of the patient were collected, along with peripheral blood samples of the proband and his parents. Whole exome sequencing (WES) was carried out through next-generation sequencing. RESULTS: Candidate variants were searched through bioinformatic analysis focusing on genes associated with hereditary aortic aneurysms. Candidate variant was verified by Sanger sequencing. The patient was found to have cardiovascular abnormalities including early-onset aortic dilatation and coarctation, and LDS syndrome was suspected. WES revealed that he has harbored a heterozygous c.1526G>T missense variant of the TGFBR2 gene. The same variant was not found in either parent and was predicted as likely pathogenic (PM1+PM2_Supporting+ PM6+PP3+PP4) based on the guidelines from the American College for Medical Genetics and Genomics (ACMG). CONCLUSION: The TGFBR2 c.1526G>T variant probably underlay the LDS in this patient and was unreported previously in China. Above finding has enriched the mutational spectrum of the TGFBR2 gene associated with the LDS and provided a basis for the genetic counseling for the patient.

Iatrogenic aortic dissection during aortic root replacement in an older Loeys-Dietz syndrome type III patient with no family history of aortic disease: a case report.

BACKGROUND: Iatrogenic aortic dissection during cardiac surgery is a rare but critical complication. At present, no strategies have been developed to prevent it. We herein report a case of intraoperative aortic dissection during aortic root replacement in an older patient with Loeys-Dietz syndrome type III who had no family history of aortic disease. CASE PRESENTATION: A 60-year-old man was admitted to the hospital for Stanford type B acute aortic dissection and given conservative treatment. He was found to have aortic root dilatation and severe aortic regurgitation. Thus, elective Bentall procedure was performed. Postoperative computed tomography showed new Stanford type A aortic dissection that may have developed due to aortic cannulation during surgery. The patient was given conservative treatment and successfully discharged to home at postoperative day 34. Although he had no family history of aortic disease, a genetic test revealed an unreported SMAD3 frameshift mutation (c.742_749dup, p. Gln252ThrfsTer7), and the patient was diagnosed with Loeys-Dietz syndrome type III. CONCLUSION: In patients with connective tissue disorder, aortic manipulations may become the cause of critical complications. Avoiding the use of invasive techniques, such as cannulation and cross-clamping, and implementing treatment strategies, such as perfusion from other sites than the aorta and open distal anastomosis, can prevent these complications, and may be useful treatment modalities. The possibility of connective tissue disease should be considered even if the patient is older and has no family history of aortic disease.

A novel pathogenic variant located just upstream of the C-terminal Ser423-X-Ser425 phosphorylation motif in SMAD3 causing Loeys-Dietz syndrome.

OBJECTIVE: Loeys-Dietz syndrome (LDS) is a heritable disorder of connective tissue closely related to Marfan syndrome (MFS). LDS is caused by loss-of-function variants of genes that encode components of transforming growth factor-ß (TGF-ß) signaling; nevertheless, LDS type 1/2 caused by TGFBR1/2 pathogenic variants is frequently found to have paradoxical increases in TGF-ß signaling in the aneurysmal aortic wall. Here, we present a Japanese LDS family having a novel SMAD3 variant. METHODS: The proband was tested via clinical, genetic, and histological analyses. In vitro analysis was performed for pathogenic evaluation. RESULTS: The novel heterozygous missense variant of SMAD3 [c.1262G>A, p.(Cys421Tyr)], located just upstream of the C-terminal Ser423-X-Ser425 phosphorylation motif, was found in this instance of LDS type 3. This variant led to reduced phospho-SMAD3 (Ser423/Ser425) levels and transcription activity in vitro; however, a paradoxical upregulation of TGF-ß signaling was evident in the aortic wall. CONCLUSIONS: Our results revealed the presence of TGF-ß paradox in this case with the novel loss-of-function SMAD3 variant. The precise mechanism underlying the paradox is unknown, but further research is warranted to clarify the influence of the SMAD3 variant type and location on the LDS3 phenotype as well as the molecular mechanism leading to LDS3 aortopathy.